Make --example be the default

lib/src/command/add.dart

@@ -153,6 +153,7 @@ For example:
     );
     argParser.addFlag(
       'example',
+      defaultsTo: true,
       help:
           'Also update dependencies in `example/` after modifying pubspec.yaml in the root package (if it exists).',
       hide: true,

lib/src/command/downgrade.dart

@@ -40,6 +40,7 @@ class DowngradeCommand extends PubCommand {
 
     argParser.addFlag(
       'example',
+      defaultsTo: true,
       help: 'Also run in `example/` (if it exists).',
       hide: true,
     );

lib/src/command/get.dart

@@ -50,6 +50,7 @@ class GetCommand extends PubCommand {
 
     argParser.addFlag(
       'example',
+      defaultsTo: true,
       help: 'Also run in `example/` (if it exists).',
       hide: true,
     );

lib/src/command/remove.dart

@@ -57,6 +57,7 @@ To remove a dependency override of a package prefix the package name with
 
     argParser.addFlag(
       'example',
+      defaultsTo: true,
       help: 'Also update dependencies in `example/` (if it exists).',
       hide: true,
     );

lib/src/command/upgrade.dart

@@ -72,6 +72,7 @@ class UpgradeCommand extends PubCommand {
 
     argParser.addFlag(
       'example',
+      defaultsTo: true,
       help: 'Also run in `example/` (if it exists).',
       hide: true,
     );

test/get/gets_in_example_folder_test.dart

@@ -31,7 +31,7 @@ void main() {
         ])
       ]).create();
 
-      await pubCommand(command, args: []);
+      await pubCommand(command, args: ['--no-example']);
       final lockFile = File(p.join(d.sandbox, appPath, 'pubspec.lock'));
       final exampleLockFile = File(
         p.join(d.sandbox, appPath, 'example', 'pubspec.lock'),

test/testdata/goldens/directory_option_test/commands taking a --directory~-C parameter work.txt

@@ -5,6 +5,8 @@ $ pub add --directory=myapp foo
 Resolving dependencies in myapp...
 + foo 1.0.0
 Changed 1 dependency in myapp!
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
@@ -13,13 +15,17 @@ $ pub -C myapp add bar
 Resolving dependencies in myapp...
 + bar 1.2.3
 Changed 1 dependency in myapp!
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
 ## Section 2
 $ pub -C 'myapp/example' get --directory=myapp bar
 Resolving dependencies in myapp...
 Got dependencies in myapp!
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
@@ -29,22 +35,24 @@ Resolving dependencies in myapp...
 These packages are no longer being depended on:
 - bar 1.2.3
 Changed 1 dependency in myapp!
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
 ## Section 4
 $ pub get bar -C myapp
 Resolving dependencies in myapp...
 Got dependencies in myapp!
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
 ## Section 5
 $ pub get bar -C 'myapp/example'
 Resolving dependencies in myapp/example...
-+ foo 1.0.0
-+ test_pkg 1.0.0 from path myapp
-Changed 2 dependencies in myapp/example!
+Got dependencies in myapp/example!
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
@@ -72,6 +80,8 @@ $ pub downgrade -C myapp
 Resolving dependencies in myapp...
   foo 1.0.0
 No dependencies changed in myapp.
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------
 
@@ -80,6 +90,8 @@ $ pub upgrade bar -C myapp
 Resolving dependencies in myapp...
   foo 1.0.0
 No dependencies changed in myapp.
+Resolving dependencies in myapp/example...
+Got dependencies in myapp/example.
 
 -------------------------------- END OF OUTPUT ---------------------------------